Created by the Medicare Modernization Act of 2003, Medicare Part D provides a prescription drug benefit to Medicare enrollees. The Part D benefit is administered by private stand-alone drug plans and Medicare Advantage drug plans.

Over the last decade, market-based approaches to pricing and negotiation of discounts within Part D have been successful in providing broad access to pharmacy services and prescription drugs. Vigorous negotiation between PBMs and pharmacies, and between PBMs and manufacturers in this highly competitive market continues to be the best approach for reducing drug costs for the federal government and Medicare beneficiaries.